Low Cohomogeneity and Polar Actions on Exceptional Compact Lie Groups

We study isometric Lie group actions on the compact exceptional groups E6, E7, E8, F4 and G2 endowed with a biinvariant metric. We classify polar actions on these groups. We determine all isometric actions of cohomogeneity less than three on E6, E7, F4 and all isometric actions of cohomogeneity less than 20 on E8. Moreover we determine the principal isotropy algebras for all isometric actions on G2.Comment: 27 pages; introduction rewritten; references updated; final version; to appear in Transformation Group

Anthropogenic impact on a pregnant Cuvier’s beaked whale (Ziphius cavirostris) stranded in Brazil

Background: Because of their usually cryptic behaviour, most knowledge on the biology of beaked whales are from records of stranded animals. Although the Cuvier’s beaked whale (Ziphius cavirostris) is the best known species of the ziphiidae family, little information on its reproduction is available. Results: Here we report on the stranding of a dead pregnant female with clear signs of anthropogenic impact, including the presence of a fishing artefact in the stomach. Conclusions: The region of the stranding (north-eastern coast of Brazil) is an area of increasing interest for oil and gas exploitation. Conservation concerns may arise from findings such as the one presented and discussed here